Casein glue



COMPOSITIONS, COATING OR PLASTIC.

UNITED STATES PATENT OFFICE.

HENRY L. PRESTHOLDT, OF MINNEAPOLIS, MINNESOTA.

CASEIN GLUE,

No Drawing.

My present invention provides a new composition of matter, hereindesignated as pa; sein glup, but which, from its broader aspoet, is anadhesive composition adapted to be used, by itself or commingled withother substances, as an adhesive coating.

The most important elements of this improved composition are casein,lime a fluorine salt, (preferably sodium fluor de) sodi- 1 um sil patp,co er mljii de and a salt o f ormic acid pre erably sodium formatel.Preferably,- however, trisfod pnif'lfo'sfiage and oil are added intotlie composi ion? I'liave obtained a very highly efficient glue oradhesive by the use of the above noted substances in accordance with thefollowing formula:

Parts.

Casein 50 to 75 Calcium hydroxide 10 to 30 Tri-sodium phosphate 5 to 20Sodium fluoride 2 to 12 Sodium silicate 3 to 18 Copper chloride 1 to 5Sodium formate to 3 Kerosene 3 to 5 astor oil 1 to 3 When a smallpercentage of calcium hydroxide is used, which is necessary in order toreduce the hardness of the glue joint on knives and tools, and theinfusible silicates are substituted, the glue ordinarily loses itswater-proof qualities, but I have discovered that when a sa |t 9fcopper, or preferably copper chloride, is use ,t e glue becomessubstantially perfectly water-proof. The addition of a salt of formicacid, such as sodium forma e, increases 1 uid life of the glue andstabilizes the glue solution so that, in practice, it may be definitelyregulated as to how long the glue will remain in liquid form andsuitable for use without any deterioration.

The above noted substances, except the oils, are commingled in drypowdered form and the oils commingled therewith are in such smallquantity that they do not make the powdered mass pasty but keep the samefrom getting into dust form. This adhesive is sold in dry or powderedform, and when Application filed April 17, 1922. S61'i3.1N0. 554,206.

it is to b; used, it wilil be introduced into wate to orm an emu sionand it is t en, 0 course, that the chemical reactions that develop theadhesive qualities of the composition, will take place. After thesereactions have taken place, the emulsion is adapted to be used as a glueor as a coating or p10 be commingled1 with other substances, suc as aint0r ca cimine which contain certain color 1 ments. W lien desired,however, the color pigments may be commingled with the dry composition.TVhen the composition is to be used as a glue, no additions to theformula given, except water, will be required.

Casein, when properly treated with solvents, will produce colloidalproperties haviiig great adhesive strength. In this formula, I usetri-sodium phosphate and sodium fluoride, (solvents). These alone willnot effect a complete solution and bring out all the colloids present incasein, and to effect a more complete solution, I introduce calciumhydroxide. This chemical also has the property of uniting with casein,forming insoluble calciumpaseippte which imparts to the glue emu sion waer-proof qualities. In order to reduce the cost of this product, sodiumsilicate is used. Sodium silicate in solu- .tion in this combination hasadhesive quali- Examines ties, but has the peculiar property of reducingthe waterproof qualities of the glue mixture. To overcome this,specifically, I introduce copper chlorideor some salt of coppeF, whichimparts, when sodium silicate is used, a remarkable resistance to hotand cold water. Sodium formate is used for the purpose of preventing thedecomposition of the casein, which takes place very quickly, andliberates ammonia, but by the addition of sodium formate, this rapidchange is prevented. The kerosene oil is commingled with the powder forthe purpose of preventing the decomposition of calcium hydroxide, whichwhen exposed to the air forms calcium carbonate. Castor oil andkerosene, while desirable, 'may be ohilt t ed fi dm tlie'compo sition.

What I claim is:

1. An adhesive composition made substantially in accordance with thefollowing formula:

Parts.

Casein 50 to 75 Calcium hydroxide 10 to 30 Tri-sodium phosphate 5 to 20Sodium fluoride 2 to 12 Sodium silicate 3 to 18 Copper chloride i- 1 to5 2. An adhesive composition made substantially in accordance with thefollowing formula:

' Parts. Casein 50 to 75 Calcium hydroxide 10 to 30 Tri-sodium phosphate5 to 20 Sodium fluoride 2 to 12 Sodium silicate 3 to 18 Copper chloride1 to 5 Sodium formate to 3 3. An adhesive composition made in ac- 20cordance with the following formula:

In testimony whereof I afiix my signature.

HENRY L. PRESTHOLDT.

